false

In JavaScript, false is a reserved word and a literal that represents the logical value for no, off, or a condition that doesn’t hold. It’s one of the two values of the boolean type, and true is the other.

Comparison operators, !, in, and instanceof produce false when their test fails, and typeof false returns "boolean". As a reserved word, false can’t name a variable, function, or parameter, and it can’t be reassigned.

false is one of the falsy values, along with 0, "", null, undefined, and a few others. The string "false" isn’t falsy, because every non-empty string is truthy. A Boolean wrapper object created with new Boolean(false) is truthy too, because every object is.

JavaScript false Keyword Examples

The false literal is one of the two boolean values, and comparisons produce it too:

JavaScript 
> typeof false
'boolean'

> 10 < 3
false
> !false
true

> Boolean("false")
true
> Boolean(new Boolean(false))
true

The comparison 10 < 3 evaluates to false, and !false evaluates to true. The Boolean() function shows that the string "false" and a wrapper object both convert to true.

JavaScript false Keyword Use Cases

  • Initializing Boolean flags that start switched off
  • Returning the negative result of a check from a predicate function
  • Disabling settings in configuration objects, such as { recursive: false }
  • Stopping a loop by setting its condition variable to false

Have a question about this? Mentor AI can show you examples, compare related terms, and point you to tutorials.

  • Ask Mentor AI
  • Pick a question and Mentor AI takes it from here.
By Leodanis Pozo Ramos • Updated Nov. 3, 2026
JavaScript Keywords Share Feedback